66990673 has 4 divisors (see below), whose sum is σ = 67053168. Its totient is φ = 66928180.

The previous prime is 66990653. The next prime is 66990733. The reversal of 66990673 is 37609966.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66990673 - 2¹⁷ = 66859601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66990653) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29611 + ... + 31792.

It is an arithmetic number, because the mean of its divisors is an integer number (16763292).

Almost surely, 2^66990673 is an apocalyptic number.

It is an amenable number.

66990673 is a deficient number, since it is larger than the sum of its proper divisors (62495).

66990673 is a wasteful number, since it uses less digits than its factorization.

66990673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62494.

The product of its (nonzero) digits is 367416, while the sum is 46.

The square root of 66990673 is about 8184.7830148392. The cubic root of 66990673 is about 406.1359623744.

The spelling of 66990673 in words is "sixty-six million, nine hundred ninety thousand, six hundred seventy-three".